City of the Sun by David Levien
Twelve-year-old Jamie Gabriel gets on his bike before dawn to deliver newspapers in his suburban neighbourhood. Somewhere en route, he vanishes without a trace. Fourteen months later, still with no sign of Jamie and having lost all faith in the police, his parents Paul and Carol are on the verge of abandoning hope. Then they meet private investigator Frank Behr, a tough, reclusive ex-cop. Abandoned by his former colleagues, separated from his wife and haunted by his own terrible past, Behr doesn't make it a practice to take on hopeless cases, but the desperate couple's plea for help awakens a personal pain he can't ignore. So begins his unrelenting quest for answers in Jamie's disappearance.